Automatic pressure-regulator for pneumatic actions of musical instruments.



PATENTED JUNE 30, 1908.

P. W. DRAPER.

INSTRUMENTS.

APPLIOATION FILED APR.3.1905.

AUTOMATIC PRESSURE REGULATOR FOR PNEUMATIC AGTIONSIOP MUSICAL W h A g VV/////// y////////////Z/// //////////////////@/////////////////////ZZ\ AA Q\ j x \\\\\\M \\\\\\\\\\\\\\\\\\\\\\X 7Z2 79-anc zLs 602224229 WaWe/ascu fly I M- 1 Q A UNITED STATES PATENT orrron FRANCIS W. DRAPER, OF DETROIT, MICHIGAN, ASSIGNOR TO FARRAND ORGAN COMPANY, OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN.

AUTOMATIC rnnsstmn-nneupa'ron FOR PNEUMATIC ACTIONS OF MUSICAL \TNSTRUMENTS.

Specification of Letters Patent.

Patented June so, 1908.

Application 'filed April s, 1905. serial No. 253,546.

- fication, reference being had therein to the adiustabl'e valves. 20

accompanying drawings.

The invention relates to pressure regus lators', more especially designed for use in pneumatic actions for automatic musical instruments, and the invention consists in the novel construction as hereinafter set forth.

Inthe drawings, Figure 1 is a longitudinal.

section through the regulator. Fig. 2 is a plan viewof a portion thereof, showing the n the construction of auto-pneumatic musical instruments, it is usual to provide in addition to the regulati store bellows,

independent means for regu ating the pressure of air used in difierent parts of the instrument, as for instance the air employed for operating the motor. The present invention relates to the peculiar construction of a regulator for this purpose; and an important feature of theconstruction is the means by which the regulator will be adjusted to operate uniformly in different positions of ad ustment of the tempo valve.

. As shown, A is a casing or box, .within which is arranged the tempo valve l3,-slidinglysecured in guides C and controlling the ort D. This port connects witha chan nel a, leading through the walls of the casing and communicating with a chamber'F thcrei n. G is a cylinder which is open at opposite ends, and one end of which communicates with the chamber F, and the opposite end with a second chamber H also within the casing. Intermediate the ends of the cylinder are ports 1, arranged in circular series and communicatingiwitli a passage J formed in the walls of the; chest intermediate the chambersF and-ll. This passage J leads to the storelbellows or other source of pneumatic pressure.

K is a piston slidable within the cylinder G,which is preferably cup-shaped inform.

L isa'springpthefree end of which is connected by a link M with the pist0n, .prefermally hold the piston K in a position within the cylinder G, where the ports I are un-' covered thereby permitting free communication between the passage J and the chamber F. As soon, however, as a partial vacuum is formed in-the passage J by reason of its connection with the store bellows, the balance of -the air pressures acting upon opposite ends'of the piston will be disturbed, resultin the inward movementof the piston by t e diiierential pressure. ment will close or partially close the ports I, so as to restrict the connection betweentlie chamber F and the passage J It is evident that by properly adjusting the'resistance of the spring L in relation to the valve, any desired pressure maybe exerted uponthe piston to draw it outward, and only when the vacuum in the chamber F is such as to pro duce a differential pressure on the piston in excess of. the tension of this spring, will there be any movement of.the piston. On the other hand, where the vacuum is such as to produce a differential pressure in excess of, the tension of the spring, the ports I will be closed or so restricted as to prevent free communication with the passage J, and as a consequence the air pressure within the chamber F is governed by the tension of the spring.

The regulator as above described is extrcmely delicate in its operation and will respond instantaneously to any change n pressure, so that a practically uniform .ssure is maintainer for the regulated air. Under practical conditions, however, the governing of'the pressure alone will not result in uniform action of .the pneumatics operated by the regulated air. This is for the reason that the volume and velocity of the air current are factors in the operation of the pncumatics as well as the pressure. As

a consequence, where a variab c restriction,

such as the tempo valvo, controls the air current, an ad ustment of the regulator This movewhich will secure a uniform. action in one position of adjustment of said valve may not the pressure, so that the regulator may not .sure is not as instantaneous.

govern with uniformity the slower speed. To overcome this defect in the present construction of regulator, provision is made for retarding the movement of the regulating valve, so that its response to change in pres- This ermits of so adjusting the tension of the spring L that it will govern with equal uniformity where the tempo valve is wide open or nearl closed. 7 The construction employed for this purpose is preferably as follows:

As has een stated, the casing A- has formed therein a chamber H which commu- 'nicates with the end of the cylinder G, and this chamber is in communication with the external atmosphere through the port 0.

P is a valve for variably restricting the port 0, which as shown is in the form of a slide pivoted at Q to the casing A. When the valve P is adjusted to restrict the port 0, the result will be that the movementol' the piston valve K, under the actuation of the differential pressure, will be retarded. Such an effect is produced for the reason that the chamber H is dependent upon the port 0 for communication with the external atmosphere, and when said port is restricted, the passage of air thcrethrough is retarded, which correspondingly retards the movement of the piston.

With the construction above described in use, the regulator is adjusted first by varying the resistance or tension of the spring L, which may be done by an adjusting screw it bearing against the spring and then by adjusting the valve I to vary the restriction of the port 0. By suitable-relative change of these two adjustments, the regulator may be placed in condition so that it will govern uniiormly'for diilerent positions of the tempo valve B, so that whether the motor is running fast under open valve or slow under a closed valve, its speed will not vary so long as the tempo valve remains stationary.

By making the valve K cup sha ed and? out of thin metal, the weight is re( need to such an extent that the factor of inertia is inconsiderable'in the operation of the regulator. The result of this is to obtain a more perfect regulation than would be otherwise y slows the motor but also changes and a chamber having restricted The advantage. of such a regulation over the ordinary regu,

on, and actuated by the differentialthereof to vary the extent of the opening between said chambers for the regulated and the unregulated pressures, and means for retarding the speed of movement of said valve.

2. A regulator for self-playing musical instruments comprising communicating chambers for the regulated and the unregulated air pressures, a freely movable valve subjected directly to oipposed air pressures and actuated by the di erential thereof to vary the extent of the opening between said chambers for the regulated and the unregulated pressures, and means for retardin the movement of air on one side of said va veto slow the action thereof.

3. A regulator for self-playing musical instruments comprising communicating chambers for the regulated and the unregulated air pressures, a piston valve controllmg the assage between said chambers for the reguated and the unregulated valve being directly subjecte pressures, a tension device for actuating said valve in one direction, means for retarding the movement of air on one side of said valve to slow the action thereof, and means dpressures, said I to opposed air for relatively adjusting said tension device Which said valve travels having one end in,

communication with the chamber for the regulated air pressure said cylinder also com- Inunicating at a different oint with the chamber for the unregulate air ressure, a tension device for actuating sai piston to open communication between said chambers for the regulated and the unregulated air pressures, means for adjusting said .tension device, and means for variably restricting the communication between said cylinder and the external atmos here whereby the speed of movement of saiil valve is regulated. 5. .A regulator for self-playing musical mstrumehts, comprising, a casing ha in formed therein a chamber forv the unregulated air, a chamber for the re ulated air,

' communication With the external atmosphere a cylinder opening at opposite ends respectively to said chamber for the regulated air, and said chamber communicating with the at mosphere and having a port intermediate its .ends communicating with the unregulated restriction between the atmospheric .air

. chamberand the external atmosphere whereby the speed of movement of said valve is regulate 6. in a mechanical player for musical instruments, a regulator comprising communicating chambers for the regulated and the unregulated air pressures, a valve subjected to o )posed air pressures and actuated by the (lill'erential thereof to vary the extent of the opening between said chambers for the regulated and the unregulated pressures, 'saidvalvc consisting of a cup-shaped piston having thin Walls, and of small mass,

whereby t inertia of the valve is slight.

7. A regulator for self-playing musical instruments comprising a ported cylinder and a freely movable piston valve subjected to oprposed air pressures and actuated by the di l'erential thereof, said valve being of a cupshape having thin walls and of small n'lass, a spring for actuatin I said valve in one direction, and a pivotal ink connecting said valve and spring, and extending within the cup. of the latter.

in testimony whereof I affix my signature in presence of two witnesses.

FRANCIS DRAPER.

Witnesses;

JAB. P. BARRY, EDWARD D. AULT. 

